I've got a host that has a class added via a hostgroup.

On the class, I add a smart variable (for testing, I assume the same matching mechanisms also apply to class params).

This is the configuration of the smart variable:

Name: loc_test
Description: test for location matching
Type: string
Default value: default
Order: fqdn hostgroup os domain location
Match: location=abc
Value: abc

Here is the output from https://foreman/hosts/testhost/externalNodes?name=testhost

--- 
  classes: 
    theclass: 
  parameters: 
    location: abc
    loc_test: default

David, can this issue be closed?

Retesting this, I found a deeper cause of my problem:

For some reason the displayed and the actual name of the location do not have the same case. At most places in the UI, the location is displayed with title case (i.e. first letter capitalized), but in the :edit, the name is entered all lower case.

I always tried matching to the lowercase version (which is also what can be seen in the YAML output and the database (taxonomies table), but actually the upcased version is matched.

Demo:

class: loctest
param: var
matcher1: location=rcv, value1: lowercase
matcher2: location=Rcv, value2: uppercase

(pruned) output:

--- 
  parameters: 
    location: rcv
  classes: 
    "bi::loctest": 
      var: uppercase

foreman=# select * from taxonomies;
 id | name |   type   |         created_at         |         updated_at         | ignore_types 
----+------+----------+----------------------------+----------------------------+--------------
  2 | rcv  | Location | 2013-01-28 12:24:14.135418 | 2013-02-11 16:26:10.407401 | --- []

This effect vanishes if the to_label function of app/models/taxonomy.rb is changed as follows:

  def to_label
    # name =~ /[A-Z]/ ? name : name.capitalize
    name
  end

thanks David, I will look into this further

David, I sent a pull request https://github.com/theforeman/foreman/pull/700 with your fix.
As a rule, I feel that changing uppercase, lowercase, etc should only be in the UI and not in business logic. The matcher should match whatever the user enters. I didn't realize that the code matches on #to_label, but apparently your test shows that it does.